Add ON DELETE CASCADE to all foreign keys in scheme

add_on_delete_cascade_to_all_fk.sql

do $$
declare 
    rec record;
    namespace_restriction text;
begin
    namespace_restriction = 'public'; 
    for rec in select 
        conrelid::oid::regclass::text as constraint_table,
        conname as constraint_name,
        pg_catalog.pg_get_constraintdef(oid) as constraint_definition
    from
        pg_catalog.pg_constraint
    where
        -- type == foreign keys
        contype = 'f' and 
        -- on_delete != cascade
        confdeltype != 'c' and
        -- namespace == your_namespace
        connamespace = (select oid from pg_catalog.pg_namespace where nspname = namespace_restriction)
    loop
        execute 
            'alter table ' || rec.constraint_table || ' ' ||
                'drop constraint ' || rec.constraint_name || ', ' ||
                'add constraint '  || rec.constraint_name || ' '  || rec.constraint_definition || ' on delete cascade';
    end loop;
end $$;